Cabin air filter in 2006 F-250 5.4L?

Can't find the answer to this, but where is the cabin air filter on my 06 F-250? I know that ford had a few large vehicles that had no cabin filters, but wasn't sure if mine was one of them. I want to change it (if I have one) because when I turn on the A/C it sounds like there's something blocking the air flow and the air output seems low.

It doesn't have one. Your problem is probably related to the blend door not opening/closing completely.